The Irish Airline Pilots Association (Ialpa) has called on the Department of Transport to establish the circumstances surrounding a hoax bomb alert on a Ryanair flight which led to the aircraft being diverted to Scotland on Wednesday afternoon.
The move comes amid concerns over why 172 passengers were not removed immediately from the aircraft, which was due to fly from Paris to Dublin, after it was forced to land at Prestwick airport. Instead, they remained on board for over two hours.
Evan Cullen, of Ialpa, said the association is conducting its own investigation, and is encouraging anyone with knowledge of what occurred to contact it.
It is understood that normal procedures in other international airports would be to remove passengers from the aircraft as soon as possible in the event of a bomb alert.
A spokeswoman for the Department of Transport said it has no plans to carry out a separate investigation into the incident, which occurred after a note was passed to cabin crew in a magazine claiming there was a bomb on board.
As it occurred in UK airspace, it was a matter for authorities there to investigate, she said.
The department was not aware of any representations made to it by Ialpa, but would not rule out its own investigation if specific evidence of concern emerged, she said.
Strathclyde police in Scotland, which is investigating the incident, defended the decision to keep passengers on board the aircraft. In a statement, it said it was as a result of a "full risk assessment" carried out by its officers. Passengers would have been evacuated immediately from the aircraft if they were found to be in any danger, it said.
Mr Cullen said Ialpa had received a number of "independent, unconfirmed reports that [ the pilot] was told not to disembark or evacuate passengers," he told The Irish Times yesterday.
It has also previously received separate reports of incidents where pilots have felt under pressure not to exercise their authority in such a situation.
The Irish Aviation Authority and the UK Department of Transport said it was not within their remit to investigate the incident. Ryanair said the incident was a matter for Strathclyde police.
Seventy-one second-year students from St Leo's College in Carlow were among those on board. Teacher Maireád Breen, who organised the four-day trip, told The Irish Times that the pilot had informed passengers on several occasions that he was "pleading" to have the passengers taken off.